Women tend to have smaller bodies than men, and differences in physiology that make blood-alcohol levels climb faster and stay elevated longer. Some studies have found that women have lower levels of the stomach enzymes needed to process the toxins in alcoholic beverages.
As a result, according to the Centers for Disease Control and Prevention, women are more prone to suffer brain atrophy, heart disease and liver damage. Even if a woman stops drinking, liver disease continues to progress in ways it does not in men, said Gyongyi Szabo, a professor at the University of Massachusetts Medical School. And research definitively shows that women who drink have an increased risk of breast cancer.
"There is no gender equity when it comes to the effects of alcohol on men versus women," Szabo said. "Females are more susceptible to the unwanted biological effects of alcohol when they consume the same amount of alcohol and at the same frequency — even when you adjust for weight."
Many women don't know this — nor do they understand what constitutes excessive drinking, said Robert D. Brewer, leader of the CDC's alcohol program. For women in the United States, anything more than one drink a day is considered excessive. That's one ounce of distilled spirits, 12 ounces of beer or five ounces of wine.
Four drinks consumed within two hours is considered binge drinking. That's about two-thirds of a bottle of wine.
"Most people do not understand what binge drinking looks like, and they don't yet recognize how dangerous it is," Brewer said. "Smoking, eating unhealthy foods, not exercising — people get what that can do to your health. But we are in a way different stage with binge drinking."